Process of treating copper-nickel-sulfid ores.



UNITED STATES PATENT OFFICE.

DARIUS PARSONS SHULER, OF SUDBURY, CANADA.

PROCESS OF TREATING COPPER-'NlCKEL-SULFID ORES.

SPECIFICATION formingpart of Letters Patent No. 697,370, dated April 8, 1902.

' Application filed August 10, 1900.

To all whom, it ntcty concern.-

Be it known that I, DARIUS PARSONS SHU- LER, a citizen of the United States, and a resident of Sudbury, in the Province of Ontario and Dominion of Canada, have invented new and useful Improvements in Processes of Treating Oopper-Nickel-Sulfid Ores to Obtain Pig-Iron Containing Nickel, of which the following is a full, clear, and exact description. My invention relates to the treatment of ores containing, besides iron and nickel, nonmagnetic elements, such as copper, in combination with sulfur. The ores treated according to my process are mixtures of copper pyrites,pentlandite, pyrrhotite, hazelwoodite, with some gersdorffite, niccolite, &c., or mag-' netic and non-magnetic nickel-iron sulfids with copper-iron sulfids.

The main product of my process is pig-iron containing a percentage of nickel, which fineness depending upon the character of the ore; but as a rule a fineness of twenty to fifty mesh will do. In this comminuted state the ore is passed through a magnetic separator of any approved construction, so as to divide it into a portion (headings) rich in magnetic constituents, and another portion (tailings) poor therein. (A) The composition of these tailings depends upon the grade of the ore and the method of separation, and will be about as follows for Sudbury pyrrhotite ores: copper, .10 to fifteen; nickel, .50 to thirty; iron, ten to thirtyeight; sulfur, twelve to forty-four; insoluble residue, one to sixtyfive; phosphorus, .10 to .50. These tailings are roasted in any furnace adapted for roasting ores containing a low proportion of sulfur, such as Browns furnace, and are then bricked or not and smelted in a shaft-furnace or other Serial No. 26,481. (No specimens.)

tained the composition of which will vary according to the strength of the magnetic field through which the ore passes in the separation. In ordinary practice probably at least two grades of headings would be required. The first would have a composition as follows: copper, 0.00 to .20; nickel, 1.50 to six; iron, fifty to sixty; sulfur, thirty-four to thirtyseven; phosphorus, 0.00 to .02. The second grade of headings would have about the followingcomposition: copper,.30 to.80; nickel, ten to thirty; iron, eighteen to twenty-eight; sulfur, ten to twenty-six; phosphorus, trace to .05.

It will be observed that as compared with the tailings the headings are very rich in iron and sulfur, low in phosphorus, but contain little copper, the amount of nickel being such in proportion to the iron that the right proportions are obtained to produce pig-iron suitable for the manufacture of nickel-steel. This increase of sulfur allows the roasting of the headings in muffle-furnaces.

The headings are first dead-roastedthat is, roasted until the sulfur has been expelled entirely, or nearly so. The roasting may be conducted first in a Herreshoff furnace until the amount of sulfur has been reduced to five per cent, and then in a Brown furnace. The roasting increases the proportion of metallic contents about fourteen per cent-2'. a, the iron increases from fifty-six per cent. in green headings to sixty-five per cent. in roasted; nickel, from three per cent. to thirty-five per cent. the. The sulfur-dioxid gas (S0 which is given oif during the first roasting operation may be disposed of in any approved manner and may be utilized in the manufacture of sulfuric acid or for any other industrial purpose. In some cases the roasting of the tail ings may be dispensed with. The headings,

generally roasted as described, are then smelt ed in an iron-furnace either alone or with the addition of Bessemer iron ore. The headings may be smelted as they come from the roasting-furnace or, better, after being made into briquets. The products of the smelting operation are lime-slag, which goes to waste, and pig-iron containing from three to twelve per cent. or more of nickel. The average contents of nickel will be from three per cent. to five per cent. The pig iron thus produced is very well suited for the direct manufacture of nickel-steel without the addition of metallic nickel or nickel oxid. This is the main advantage of my process, inasmuch as it aifords an economic and elficient means of obtaining nickel-steel or pig-iron suitable for the first production of such steel, while at the same time saving most of the iron in the nickel ore and greatly lessening the cost of the nickel contained in the steel.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent- 1. The herein-described process of treating ores of the class described, that is, ores containing nickel-iron sulfids with copper-iron sulfids, which consists in subjecting the comminuted ore to magnetic separation so as to produce therefrom headings and tailings, the headings being richer in iron and sulfur than the tailings, but generally poorer in nickel; thus bringing about, by the magnetic separation, a variation or readjustment of the relative proportions of iron and nickel, so as to produce the proportions which are proper for the making of nickel-steel, then roasting the headings, and finally smelting them to produce pig-iron containing a proportion of nickel which makes it suitable for the direct manufacture of nickel-steel.

2. The herein-described process of treating ores of the class described, that is, ores containing nickel-iron sufids with copper-iron sulfids which consists in subjecting the comminuted ore to magnetic separation so as to produce therefrom headings and tailings, the headings being richer in iron and sulfur than the tailings, but generally poorer in nickel; thus bringing about, by the magnetic separation, a variation or readjustment of the relative proportions of iron and nickel, so as to produce the proportions which are proper for the making of nickel-steel and then smelting the headings, to produce pig-iron containing a proportion of nickel which makes it suitable for the direct manufacture of nickelsteel.

3. The herein-described process of treating ores of the class described, that is, ores containing nickel-iron sulfids with copper-iron sulfids which consists in subjecting the comminuted ore to magnetic separation so as to produce therefrom headings and tailings, the headings being richer in iron and sulfur than the tailings, but generally poorer in nickel, thus bringing about, by the magnetic separation, a variation or readjustment of the relative proportions of iron and nickel, so as to produce the proportions which are proper for the making of nickel-steel, then roasting the headings, and finally smelting them with the addition of Bessemer iron ore, to produce pig-iron containing a proportion of nickel which makes it suitable for the direct manufacture of nickel-steel.

t. The herein-described process of treating ores of the class described, that is, ores containing nickel-iron sulfids with copper-iron sulfids which consists in subjecting the comminuted ore to magnetic separation so as to produce therefrom headings and tailings, the headings being richer in iron and sulfur than the tailings, but generally poorer in nickel, thus bringing about, by the magnetic separation, a variation or readjustment of the relative proportions of iron and nickel, so as to produce the proportions which are proper for the making of nickel-steel, and then smelting the headings, with the addition of Bessemer iron ore, to produce pig-iron containing a proportion of nickel which makes it suitable for the direct manufacture of nickelsteel.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

DARIUS PARSONS SI'IULER.

Witnesses:

C. M. Boss, F. F. LEMIEUX. 

